This document summarizes a lab on 1D arrays presented by TA Nada Kamel. The lab covers what arrays are, how to declare and initialize them, and how to access array values using indexes and loops. It also provides two hands-on problems - the first calculates the sum of a Fibonacci series, and the second traces the contents of two arrays after a series of operations.

1. Lab 9
CS106 - Fundamentals of Computer Science
Presented by TA. Nada Kamel

2. Agenda
 1D Array
 Hands-on problems
Presented by TA. Nada Kamel

3. 1D Array
Presented by TA. Nada Kamel

4. What is an array?
An array is a collection of data elements of same data type.
Presented by TA. Nada Kamel

5. Array Declaration
dataType arrayName[arraySize];
For example,
an array containing 5 integer values of type int called foo could be
represented as:
int foo[5];
Presented by TA. Nada Kamel

6. Array Initialization
double balance [4] = { 1000.0, 2.0, 3.4, 7.0 };
Presented by TA. Nada Kamel
int bar [5] = { 10, 20, 30 };
int baz [5] = { };

7. Accessing Array Values
The syntax to access a single element in an array is:
arrayName[index]
Presented by TA. Nada Kamel
Example 2
foo[2] = 7; // Intializing index 2 of array foo with 7
Example 1
x = foo[2]; // Storing the value of foo[2] in variable x
cout << x; // Output is 77

8. Accessing Array Values (Cont.)
The syntax to access All values of an array is by using a loop.
int foo [] = {16, 2, 77, 40, 70};
int result=0;
for ( int n=0 ; n<5 ; n++ )
{
result += foo[n];
}
cout << result << endl;
Presented by TA. Nada Kamel
If no value in the square brackets, you
have to initialize the array to have a size in
the memory.
// result = 16+2+77+40+70 = 205

9. Hands-on Problems
Presented by TA. Nada Kamel

10. Problem 1
Write a C++ program that takes a positive integer value for n (not more than
55) and computes the sum of the following series:
1 + 1 + 2 + 3 + 5 + 8 + 13 + 21 + ...... + n
Presented by TA. Nada Kamel

11. int n;
cin >> n;
if (n < 1 || n > 55)
cout << “Please enter a positive number.n”;
else
{
int values[55], sum = 0;
for (int j = 0; j < n; j++)
{
if(j == 0 || j == 1)
values[j] = 1;
else
values[j] = values[j-2] + values[j-1];
sum += values[j];
}
cout << “Sum of value(s) is ” << sum << endl;
}

12. Problem 2
Trace the following code
int j;
int one[5], two[10];
for (j = 0; j < 5; j++)
one[j] = 5 * j + 3;
cout << “One contains: ”;
for (j = 0; j < 5; j++)
cout << setw(5) << one[j];
cout << endl;
for (j = 0; j < 5; j++)
{
two[j] = 2*one[j] - 1;
two[j + 5] = one[4 - j] – 1 + two [j];
}
cout << “Two contains: ”;
for (j = 0; j < 10; j++)
cout << setw(5) << two[j];
cout << endl;

13. Output
One contains: 3 8 13 18 23
Two contains: 5 15 25 35 45 27 32 37 42 47
Presented by TA. Nada Kamel

14. Any Questions?
Presented by TA. Nada Kamel